Having been in the HVAC industry for over 30 years, let me share some info on that blower wheel. It really is not on backwards - the wheel is what is called a "backward-inclined" wheel. Unlike traditional "forward-curved" wheels (AKA squirrel cage), the BI wheel is capable of much higher static pressure, i.e. more power to overcome air flow restrictions & produce much higher suction power.
That upgraded wheel should produce a good deal more suction power. Hope it works for you.